A magnetic disk device typically includes, in a housing, a magnetic disk, a spindle motor which supports and rotates the magnetic disk, a head stack assembly (HSA) which supports a magnetic head, a voice coil motor which moves the HSA, a flexible printed circuit board unit (hereinafter, FPC unit), and the like.
The HSA includes a bearing attached to the housing, and a plurality of arms which are stacked in the bearing and extend from the bearing. The magnetic head is attached to each arm via a suspension. The FPC unit including a base portion and a relay portion (hereinafter, relay FPC) that are integrally formed. On the base portion, for example, an electronic component and a connector are mounted, and the base portion is fixed to the housing. The relay FPC has a band shape which is bent and extends from the base portion to the vicinity of the bearing. The extended end portion of the relay FPC constitutes a connection portion, which is fixed to the bearing of the HSA (for example, by a screw).
The relay FPC is bent with respect to the base portion. When the bent state of the relay FPC is unstable, the relay FPC may influence precise movement of the HSA, as the relay FPC is connected with the HSA.